Change-speed transmission mechanism



June 26, 1951 c. M. O'LEARY CHANGE-SPEED mmsmssxou MECHANISM OriginalFiled June so, 1945 5 Sheets-Sheet 1 I I I I I I I I I I r I ullif 4INVENTOR. C'&ar/e; M 01/ e rg.

June 26, 1951 c. M. OLEARY CHANGE-SPEED TRANSMISSION MECHANISM OriginalFiled June 30, 1945 5 Sheds-Sheet 2 INVENTOF m h a w J ,w a V. B

June '26, 1951 c, Q'LEARY 2,558,193

CHANGE-SPEED TRANSMISSION MECHANISM Original Filed June 30, 1945 5Sheets-Sheet 3 INVEN TOR.

Cid/Z915 )7. dye

5 Sheets-Sheet 4 uvmv'mn CZQv-ZeJ M Chi a y- C. M. O'LEARY CHANGE-SPEEDTRANSMISSION MECHANISM 375p) xii/4 June 26; 1951 Original Filed June 30,1945 June 26, 1951 c. M. O'LEARY 2,558,193

CHANGE-SPEED TRANSMISSION rmcmmzsm Original Filed June 30, 1945 5Sheets-Sheet 5 Q A58 439 E E I E 4 2' i 5 4.6 Y mmvron C'Zarle: 01/ erg.

iwi, '13..

finale.-

iatented June 26. 1951 CHANGE-SPEED TRANSMISSION MECHANISM Chm-lee M.OLeary. Los sel, Calif. Original application June 30, 1945, Serial No.

Divided and this application March 29, 1946 Serial No. 657,959

6 Claims. I

The present invention relates to a power transmission mechanism which isparticularly adapted for use in heavy duty hoisting operations, such asthose encountered in oil well drilling and particularly in the case oideep wells; and this application is a division of applicant's copendingapplication, Serial No. 602,619, filed June 30, 1945.

A very large portion of the total drilling time and,thereiore, of thecost of the operation is spent in pullingthe drilling stem from the wellto renew the drilling bit and then returning the stem and bit. todrilling position. In view of the heavy weights involved on the hoistingdrum, very large amounts of power and great flexibility of control arerequired to pull the drill stem from the well as rapidly as possible inorder to reduce the waste time. In addition, very heavy duty andrelatively expensive braking equipment is now used for the hoisting drumto control the descent of the drill stem in the hole.

In the past, because of its great power and flexibility, steam drivenapparalus has given superior performance. However, the steam boilers andengines required to operate a deep well drilling rig are very large,expensive, and difllcult to transport. Attempts have been made in thepast to approximate steam engine performance by the use of a combinalionof one or more internal combustion engines connected to the hoistingdrum through a hydrokinetic torque converter. Such a combinationprovides an exceedingly high starting torque which is required, and adesirable automatic decrease in torque ratio as the speed of the drumincreases during hois.ing operations. However, the efliciency ofhydrokinetic torque converters is very low, except at a fixed speedratio, and in the prior mechanisms ithas not been possible to maintainthe torque ratio on a converter at or near the point of maximumeillciency during any appreciable portion of the hoisting operation. Asa result, the torque converters have been subject to destructive heatgeneration, and it has not been possible to realize their fulladvantage. heat generation in the torque converter, it has not beenpossible to operate with the output of the converter either stationaryor operating at very low speeds for any appreciable period of time.

The-above defects in prior torque converter operated drilling rigsare,.to a large extent, overcome by the use of the apparatus disclosedin applicant's copending application, Serial No. 571,656, filed January6, 1945, wherein the torque In addition, due to the through an automatictwo-speed transmission and a manually selectable change-speedtransmission which will provide a plurality of different torque ratiosin the drum drive. The automatic transmission is so arranged as todecrease the torque multiplication ratio between the torque converterand the drum when the speed ratio of the converter exceeds the ratio ofits eflicient operating range. The decreased toque multiplication ratiothus provided automatically restores the converter to its minimumeflicient speed ratio without changing the speed of or the torqueapplied to the hoisting drum. With the apparatus of said copendingapplication, it is possible for the operator, in the exercise of hisjudgment, to preselect a speed ratio in the manual transmission whichwill approximate that required to hoist a stand of drill pipe, and oncethe hoisting has started the automatic transmission will operate tomaintain the speed ratio of the converter in its emcient range providedthe proper speed ratio in the manual transmission was properly selected.However, there is a substantial range in torque on the hoisting drumfrom the high starting torque to the minimum torque during the hoistingof each standpf drill stem, and, consequently, if the speed ratio of themanual transmission is not properl selected the torque range availablewithin the efficient speed ratio range of the torque converter may notbe suiiicient, in which event the torque converter will operate in partin an ineflicient range. Moreover, the operator has no way of knowingwhether the torque converter is operating at an efficient speed ratio ornot, and, consequently, may continue to operate the apparatus underinefllcient conditions.

Accordingly, it is the general object of the present invention toprovide an improved form of power transmission system including ahydrokinetic torque converter and a manually operable change-speedtransmission capable of being shifted under load, and incorporatingmeans for indicating to theoperator when a shift in speed ratio isnecessary or desirable as well as the character of the speed ratiochange required,

Other objecls and advantages will become apparent from the followingspecification, the accompanying drawings, and the appended claims.

In the drawings,

Figure 1 is a more -or less diagrammatic plan view of the completedrilling mechanism excluding only the rig and sheaves which areconnected in the usual manner by a cable to the hoisting drum;

converter is connected to the hoisting drum 5a Figure 2 is an enlargedelevation view partly in section showing differential cooling mechanismY for one of the torque converters;

Figure 3 is a longitudinal section taken through the combined automaticand. manually controlled change-speed transmission shown in Figure 1;

Figure 4 is a further enlarged fragmentary, longitudinal section of aportion of the transmission shown in Figure 3;

Figure 5 is a fragmentary section taken on the line 5--5 of Figure 4;

Figure 6 is a transverse section taken on the line 6-6 of Figure 4;

23 and 21 may be connected to the hoisting drum by energizing clutch I9and de-energizing clutch 39. At this time the slush pumps may bedisconnected by de-energizing the clutches 32 and 33, thus makingavailable the full power of all three members for hoisting. Duringdrilling operations, the clutch I9 may be tie-energized and the clutches32 or 33 energized. In that case, engines 23 and 21 will drive therotary table I and one or both of the slush pumps 3, while. the

engine I5 will remain connected to the hoisting Figure 7 is aperspective view of the control and Figure 13 is a graph showing thetorque char-.

acteristics of the engine and torque converter employed in the preferredform of the invention.

Referring to Figure 1, the complete apparatus includes a rotary table I,a hoisting drum 2, and slush pumps 3, of conventional construction. Itwill be understood that the drum is connected to the hoisting sheaves ofthe drilling rig in the usual manner by means of a cable 4, which iswound on the drum. The drum 2 is adapted to be rotated by a sprocket 5connected in the usual manner by a clutch 6 to the drum shaft and whichis driven by means of chains 1 from a sprocket on the output shaft 8 ofa change-speed transmission 9. The input shaft ID of the transmission isconnected by a chain II. to a sprocket fixed to a shaft I2. The shaft I2constitutes the output shaft of a hydrokinetic torque converter I3, theinput shaft I4 which is connected to an internal combustion engine I5.The shaft I2 also carries a double sprocket I6 adapted to carry chainsI1 and I8. The double sprocket I6 normally runs freely on the shaft I2but may be fixed thereto by energization of a pneumatic clutch,indicated diagrammatically at I9. Chain I'I runs over a sprocket onshaft M which is the output shaft of a second torque converter 22connected to a second engine 23. The shaft 2I is also connected by achain 24 and suitable sprockets to a shaft 25 which constitutes theoutput shaft to a third hydrokinetic torque converter 26, the input ofwhich is connected to a third engine 21. Shaft 25 is connected by meansof a chain 28 and suitable sprockets to a countershaft 29 carrying apair of sprockets 30' and 3|. The sprockets 30 and 3| normally runfreely on the shaft 29 but may be fixed thereto by actuating either oneor both of a pair of pneumatic clutches indicated diagrammatically at 32and 33. The sprockets 30 and 3i carry chains 34 and 35, respectively,which drive the slush pumps 3.

The previously mentioned chain I8 on the double sprocket I6 is connectedto a sprocket 36 on an input shaft 31 of a table transmission 38. Thesprocket 36 normally runs freely on the input shaft 31 but may beclutched thereto by energizing a pneumatic clutch 39. The output shaft40 of the transmission 38 is connected by means of a chain 4| to therotary table in the usual manner.

As a result of the above connections, during hoisting operations, allthree of the engines [5,

drum through the transmission 9. The engine compounding features of thisapplication are claimed in applicants copending application, Serial No.676,450, filed June 13, 1946.

As best shown in Figures 1 and 3, each of the hydrokinetic torqueconverters I3 is provided with a differential cooling mechanismindicated generally at 42. This mechanism is preferably constructed inthe manner set forth in greater detail in said copending application,Serial No. 571,656, now abandoned, and disclosed and claimed inapplicants copending application, Serial No. 666,626, filed May 2, 1946.Briefly stated, the mechanism includes a cooling radiator 43, suitableconduits 44 and 45 for circulating the operating liquid of the converterthrough the radiator, and an air circulating fan 46 which isdifferentially driven from the input shaft I4 and the output shaft I2 ofthe converter by a differential mechanism 41 and a pair of chains 48 and49. The chain 48 is trained over a suitable sprocket on the output shaftI2 of the converter and about a sprocket 50 associated with thedifferential mechanism. The chain 49 is similarly trained over asuitable sprocket on the input shaft of the torque converter and over asprocket 5i associated with the differential mechanism.

As best shown in Figure 2, the differential mechanism comprises a casing52 which journals and supports a shaft 53 which carries the sprocket 50,and a second shaft 54 which carries the sprocket 5|. The shaft 53 isprovided with a spur gear 55, and-the shaft 54 is provided with a largerspur gear 56. A plurality of planetary gear clusters co-operate with thegears 55 and 56, and one of such clusters appears in Figure 2. As thereshown, each planetary cluster includes a spur gear 51 and a spur gear58, the two being integrally connected together and journaled in a cage59. The cage in turn is journaled for rotation about the axis of shafts53 and 54 by suitable bearings on the casing 52 and also provides abearing support for the inner ends of the shafts 53 and 54. Formedintegrally on the planetary cage 59 is a bevel ring gear 66 which mesheswith a bevel gear 6| on a vertically extending shaft 62 which isjournaled in a projecting portion 63 of the casing 52. The upper end ofthe projectin portion 63 of the casing rotatably supports a fan shaft 64for the fan 46, and the shafts 62 and 64 are connected by means of bevelgears 65 and 66.

It will be noted that when the planetary cage 59 is held stationary andeither the shaft 53 or the shaft 54 rotated, that the shaft 53 willrotate at a higher speed than the shaft 54, due to the difference insizes between the intermeshing sets of gears. The relative sizes ofvthegears are so selected that the ratio of speeds between the shaft 53 andthe shaft 54, when the planetary cage 59 is stationary, is equal to thespeed ratio of the torque converter when operating at its maximumeiiiciency. In the usual case. the speed ratio of the output of thetorque converter to the input at maximum efficiency is betweenfourtenths and five-tenths. Consequently, the relative sizes of thegears 88 through 58 will be selected to provide a corresponding ratiobetween the shafts 58 and 88. As a result of this arrangement, when thetorque converter is operating at maximum efficiency the cage 88 and,therefore, the fan 88 will be stationary. However, as the speed ratio ofthe converter departs from its ratio of maximum efliciency in eitherdirection, the fan will be rotated in one direction and the other at aspeed approximately proportional to the extent to which the speed ratioof the converter departs from its ratio of maximum ethciency.Consequently, the cooling effect of the differential cooling mechanism42 will be generally proportional to the amount of heat generated in theconverter.

If desired, a small auxiliary cooling unit may be employed in connectionwith the converter which will dissipate at all times the amount of heatgenerated when the torque converter is operating at maximum eificlency.The total-cooling effect will then be the sum of the effects of the twounits.

The remaining members 28 and 21 are equipped with similar cooling units42 which need not be further described.

The interior construction of the transmission 8 is best ShOlMl inFigures 3. 4, and 6. As-there shown, the unit comprises an automaticplanetary two-speed transmission 81 and three manually controlledtwo-speed planetary transmissions 88, 58 and 18, all of which areconnected in series. All four of the transmissions 61, 88, 68 and iiiare identical in construction except for a difference in the speedratios they provide. and the fact that transmission 81 is automaticallyoperated while the remaining transmissions are manually controlled.

As best shown in Figure 4, the input shaft I8 is journaled in suitablebearings II carried by the housing 12 of the transmission. This shaft isprovided with a bored opening 18' through which lubricating oil maybesupplied, and at its right-hand end is counterbored to receive a tubularpilot extension 14 which is fixed to the output shaft 8 and extendedentirely through the transmission. The right-hand end of the input shaftin is provided with a gear 15 adapted to mesh with a plurality of planetgears 18, each of which has fixed thereto a smaller planet gear Tl whichis in mesh with a ear 18 on a tubular shaft 18. Shaft 18 is supported ina suitable antifriction bearing 88 carried by a web 8| formed in thehousing 12 and is also supported upon the by the shafts l8 and 18,respectively. As a result of this construction, clockwise rotation ofthe shaft i0 as viewed from the output end of the transmission tends torotate the planet cage 82 in counterclockwis direction. However, if suchrotation of the cage is prevented. clockwise rotation of the shaft IDwill rotate shaft 18 in the same direction at a reduced s eed ratio. Inorder to prevent such counterclockwise rotation of the planet cage 82,there are provided a plurality of one-way brake blocks 85 which arefitted within openings 88 formed in the casing 12 and are held inposition by means of cover plates 81.

.s Thethreeblocksliarespacedequallyaround the cage 82, as best shown lnligure 8. A-spring 88 normally acts to wedge the blocks between the coverplate 81 and the cylindrical periphery of cage 82. Thus, the threeblocks 8! acts as a one-way brake between the stationary casing and thecage 82, operating to prevent counterclockwise rotation of the casing.as viewed in Figure 8, so that the transmission unit 81 will provide anincrease torque multiplication.

When it is desired to operate at a one-to-one ratio through the unit 81,it is only necessary tolock the planet gears against rotation abouttheir own axes. This is accomplished by means ofa plurality of clutchcones 88, one of which is fixed to each of the planet gear sets, and aco-operating clutch plate 88 provided with four coned clutch rings 8|,one for each cone clutch element 88. The clutch plate 88 is slidableaxially on the shaft l8 and is also free to rotate with respect thereto.When the clutch plate 88 is shifted to the left, as viewed in Figure 4,the cone clutch elements 88 are gripped by the cone clutches 8| and heldagainst rotation about their own axes. This pro- .vides a directone-to-one drive between the gears II and I8. During this condition, thecarriage 82 rotates freely in a clockwise direction, as viewed .inFigure 6, at the same speed as the shafts l8 and 18.

Means are provided to shift the clutch plate 88 into clutching positionwhen the shaft I8 reaches a predetermined speed. This means comprises anantifriction thrust bearing 82 between the clutch plate 88 and ahardened ring 88. The ring 88 in turn is adapted to be forced to theright, as viewed in Figure 4, by projection 84 on an arm 85 which ispivotally mounted upon a ring 86 surrounding the shaft I8 and fixedthereto. The extremity of the arm 85 carries a cylindrical weight 81which tends to swing the arms outwardly with a force whichis a functionof the speed of the shaft 18. Two weighted arms 85 are provided, eachhaving a weight 81, as best shown in Figures 4 and 5. At each end ofeach of the weights there is provided a hexagonal projection 88 adaptedto fit a correspondingly shaped hexagonal recess in a spring bracket 88,as a result of which the spring brackets may be mounted on the ends of'the weights in any desired angularpo'sition around the axes of theweights 81. The bracket is held in the desired adjusted position' bymeans of a nut. Extending between the brackets on the weights are a pairof springs I which constantly act to hold the weights and, therefore,the arms inwardly against the-action of centrifugal force. 7 The tensionof the springs may be adjusted by adjusting the angular position of thespring brackets 88 with reference to the cylindrical weights 81. Thestrength of the springs is preferably such that the weights will notmove outwardly until the speed of the shaft Ill reaches a speedcorresponding to the speed at which the torque converter is operating atits maximum eflicient speed ratio, as more fully set forth inapplicant's aforementioned copending application, Serial No. 571,656. Itis sufficient to state here simply that the centrifugal weights 81 andassociated mechanism operate the clutch and thus shift the transmissionelement 61 into arcondition of direct drive when the speed ratio of thetorque converter reaches a desired maximum value. The torquemultiplication ratio of the transmission 81 when the clutch rings 8| aredisengaged, is preferably in the order of two to one, with the resultthat engagement of the clutches 8| cuts the 7 torque multiplicationbetween the torque converter and the hoisting drum approximately inhalf. As a result, for a given load on the hoisting drum the torque onthe converter will be doubled and the speed ratio of the converterreduced to half that at which the engagement of clutches 9| occurred,without any change in the speed of output or the torque applied to thedrum. This combination of a hydrokinetic torque converter and anautomatic two-speed transmission is claimed in applicants copendingapplication, Serial No.

647,677, filed February 15, 1946.

Each of the remaining transmission units 68, I and II is identical inconstruction and mode of operation to the above described transmissionunit 51 except that they provide different torque multiplication ratioswhen the cone clutches are released and the cone clutches are controlledmanually. As best shown in Figure 4, the preferred method of operatingthe clutch plates of the manually controlled transmission units is byair pressure. Thus, as there shown, the clutch plate l! for thetransmission unit 68 is shifted to the right to effect engagement of thecone clutches I02 by means of an annular movable cylinder element IIIwhich bears against an antifriction thrust bearing ill to shift theclutch plate llll'to the right, as viewed in Figure 4. The annularcylinder; element co-operates with an annular piston I 05 which issupplied with operating fluid through a passageway I06 and a conduitllll. As a result, upon application of fluid under pressure to theconduit I01, the cone clutches I02 will be engaged and the transmissionunit 68 locked in a one-to-one ratio. When the fluid pressure isreleased, the clutch plate "II will disengage and the planetary cage I08will be held against clockwise rotation by a plurality of oneway brakeblocks "9a similar in construction and mode of operation to thepreviously mentioned brake blocks 85. Under these conditions,transmission unit 68 will provide an increased torque multiplicationbetween a gear I09 on the righthand extremity of shaft 19 and a gear IID on the left-hand extremity of a tubular shaft I l I which extendsover the pilot projection 14 on shaft 8 and which is journaled inantifriction ball bearings H2 carried by a web N3 of the casing 12.

It will be understood that the shaft I II is connected by means of thetransmission unit 69 to a fourth tubular shaft intermediate thetransmission units 69 and I0, and that the fourth tubular shaft will beconnected in the same manner between transmission unit Hi to the outputshaft 8 of the transmission. The construction and mode of operation ofthe transmission units 69 and being identical to that of thetransmission unit 68 is not illustrated in detail and need not befurther described except to note that the torque multiplication ratiosprovided by the transmission units 68, 69 and 10 differ from each otherin such a manner that by selectively engaging or disengaging theoperating clutches of one or more of the three units a total of eightdifferent speed ratios may be obtained. Moreover, these eight differentspeed ratios may each differ from each other successively by the samepercentage. For example, if the sizes of the gears in the threetransmissions are so chosen that transmission unit 68 gives a torquemultiplication of 1.26, transmission unit 59 gives a torquemultiplication ratio of 1.59, and transmission unit 10 gives a torquemultiplication ratio of 2.50, then the three units of the transmissionwill provide the following 8 eight torque ratios by energization of theclutches of the indicated units:

thus provided is approximately 26 percent greater than the precedingtorque ratio. It will be understood, however, that any desired torqueratios may be provided by suitably proportioning the gears of thetransmission unit.

In addition to the above, each of the above torque ratios is doubled bythe automatic transmission 61 when the speed of the shaft 19 is below apredetermined value. Consequently, the automatic transmission provideshigher starting torque ratios and automatically cuts those ratios inhalf when the shaft 19 reaches a predetermined spe d.

The cone clutches of the transmission unit 61, 68, 69 and I0 may beself-releasing when the clutch applying force is relieved or, ifdesired,

clutch release springs may be provided in the usual manner.

An important feature of the form of transmission, as illustrated anddescribed above, resides in the fact that all of the gears of thetransmission are constantly in mesh and a shift from one ratio toanother is effected simply by engaging or disengaging the cone clutchelements. Consequently, there is no possibility of dropping the loadincident to a shift from one gear ratio to another. Moreover, the coneclutch units which are engaged to effect a direct connection are eachsubject to a torque loading which is less than on fourth of the inputtorque. In fact, with a unit designed to provide a two-to-one ratio whenthe cone clutches are disengaged, the torque applied to each of the coneclutches during direct drive is only about 18 percent of the total inputoutput torque of the unit. When the cone clutches are released toincrease the torque ratio, the planet cages immediately slow down butare prevented from rotating reversely by the one-way brake blocks 85,Mile, etc, with the result that the increase torque multiplicationbecomes effective without any cessation in the drive impulse to thedrum. The one-way brake blocks themselves, being located a substantialdistance from the center of rotation, are subject to relatively lowholding forces for a given delivered torque.

A further feature of the transmission resides in the fact that the toothloading between the gears being distributed between the four sets ofplanet gears is only one-fourth that of the corresponding transmissionof conventional design. Moreover, what is more important, none of thetorque loads transmitted through the transmission subject the shafthearings to any radial loads. Consequently, the bearings, such asbearings 83, 84, 80, etc., need only be large enough to maintain theshafts in 9 mission and is reduced by reason of location of the bearingsat a substantial distance from the axis of the main transmission shaft.The braking blocks 85, being equally spaced around the cage 82, alsoassist in keeping the shafts in alignment. Accordingly, the design ispeculiarly suited to the transmission of the very heavy torques requiredfor oil well hoisting drums.

Another feature of the transmission which is of importance in welldrilling operations resides in the fact that in the event of failure ofthe air pressure supply for operating the clutches, or of failure of theclutches themselves the transmission automatically shifts into maximumtorque multiplication. Consequently, therev is no danger of dropping aload on the hoisting drum. Ready access may be had to the one way brakeblocks for inspection and replacement.

An important feature of .the transmission 3 resides in the fact that itis constructed to a large extent from a plurality of identical parts,with a consequent saving .in cost. All of. the planetary cages such asthe cages 82 and I08 and the similar cages in the transmission units 69and III are identical in construction. This is achieved by locating theaxes of the planet cluster gears in each of the transmissionson the samecenter lines. This can be done and a difference in torque multiplicationratio still provided by simply changing the relative sizes of the gearsin the cluster. Likewise, the cone clutch units and the clutch plates ofall four of the transmission units are identical, the operatingmechanisms for the three transmission units 68, 69, and I are likewiseidentical and the one-way brake blocks of all four units are the same.As a result of this fact, there is provided at low cost a very ruggedeight speed transrrission which can be shifted under full load and whichalso incorporates an automatic two speed transmission.

' I 10 I33, which is connected in any suitable mannei to the conduit II"for the air clutch operating piston and cylinder unit I93, I35, oftransmission unit 63, and an exhaust port I34 which communicates withthe atmosphere. The particular valve illustrated more or lessdiagrammatically for rotating them are so constructed that when Meansare provided in the form of a single control lever for selectivelyactuating the clutches and the transmission units 68, 69 and III toproduce the eight progressively increased multiplication ratios referredto above. This means, as

best shown in Figures 7 through 12, comprises a control box indicatedgenerally at II4 having suitably mounted therein three three-way controlvalves H5, H6, and III for controlling the operation of the fluidoperated clutches in the transmission units 69, 69, and IIIrespectively. Likewise mounted within the control box is a camshaft II8having cams II9, I20. and I2I adapted respectively to control theoperating plungers I22, I23, and I24 of the valves H5, H6, and III.respectively. The camshaft is provided with a pinion I26 adapted tocooperate with a gear sector I2'I fixed to a control shaft I23 having anoperating handle I29. The operating handle projects through a slot I30formed in an arcuate wall portion I3I of the control box II4. Alongsideof the slot are provided suitable indicia. such as the numbers onethrough eight, representing eight torque ratios available in thetransmission.

The operating cylinders and pistons for the clutches in the transmissionunits 68, 69 and III are preferably pneumatically operated, in whichevent the three control valves H5, H6, and Ill may be any desired orconventional form of three-way air valves. Thus valve II5 may be athree-way air valve having an inlet port I32 which may be connected toany suitable source is of the type in which the outlet port I33 isnormally in communication with the exhaust port I34. and communicationis blocked between the ports I32 and I33. The trapped air pressure inport I32 acts to hold the valve operating plunger I22 in its downwardlyprojected position. When the valve operating plunger I22 is forcedupwardly, as viewed in Figure 9, communication between ports I33 and I34is closed, and comr -unication between ports I32 and I33 is open, thuspermitting air under pressure to flow to the operating cylinder I33 ofthe transmission unit 08. The remaining three-way valves III and Ill aresimilarly constructed and connected to thetransmission units 99 and II,respectively.

The valve operating cams and the mechanism the operating lever I23 isswung from the upper end of slot I39 to the lower end of the slot thevalve cams II9, I29 and I2I rotate through seveneighths of a revolution.Each cam has a diflerent arrangement of peripheral lifting surfaces toeffect operation of one or more of the respective plungers I22, I23 andI24 for the different positions of the camshaft. Thus Figures ,9 to 12show the position of the parts when the operating lever is opposite theindicia 8 alongside the slot I30, in which all three of the plungersI22, I23 and I24 are in their lowermost positions thus exhausting airfrom all three of the clutch operating cylinders and providing themaximum torque multiplication through transmission 9. -Upon movement ofthe operating handle from the indicia 8 to the indicia I, the camshaftwill be rotated in a direction indicated by the arrows in Figures 10through 12 by oneeighth of a revolution, thus bringing the raisedportion I35 on cam II9 into position in which I the elevation of theplunger I22 of valve II! is effected. It will be noted that on acorresponding movement of the cams I20 and I2I no change in the positionof plungers I23 and I24 occurs. On the next increment of movement of thecamshaft IIB, plunger I22 will be lowered and plunger I23 will beelevated by the raised .portion I36 on cam I29. No change will takeplace in the condition of valve 1. On the next increment of movementplungers I22 and I23 will be elevated by raised cam portions I31 and I38on cams H9 and I29 without any change in the condition of valve .I II.On a further increment of movement plungers I22 and I23 will be releasedand plunger I24 will be elevated by the raised portion I39 on cam I2I,thus eliminating the torque multiplication available in transmissionunit III for the first time. increment of movement plungers I22 and I24will be elevated by the raised cam portions I43 and HI, and the plungerI23 will be released by cam I2I. On the next increment of movementplunger I22 will be released by cam H9, and plungers I23 and I24 will beelevated by the raised portions I42 and I43 on cams I29 and I2Irespectively. On the final movement of the camshaft all three of theplungers will be elevated by the raised portions I44, I45, and I46. Itwill be noted that the sequence of operation of the three valves is suchas to produce the eight successive speed ratios referred to above of airunder pressure, not shown, an outlet port 76 in the proper order.

On the next end of the co-operating valve plunger. the plunger-s arenormally urged downwardly. as

. a ll Itwill be noted that when it is necessary to release one valveplunger and elevate another to effect a ratio change that the releasingand eletating operations occur Simultaneously and thus v vent theimpositionof abnormal loadcondions on any of the parts. Each of theelevated portions of the cams ll l, Ill, and I! is tim vid'ed with adepression adapted to fit the rounded since Viewed in Figure 8, eitherby a spring or by the air pressure at port I12, 01 both, the recesses inthe raised portions of the cams operate as detents to retain the shaftlever I29 in any desired position of adjustment. I

- An important feature of the apparatus resides in the indicating deviceshown in Figures 7 and 8 for indicating the speed ratio and eillciencyat which the torque converter is operating-in order to guide the drillerin selecting the proper speed ratios for transmission 9 by means of thelever I28.

The eiiiciency indicator may comprise any suitable mechanism forindicating the speed ratio at which the converter is operating but, forconvenience of the operator, it is preferably calibrated in accordancewith the efficiency or the particular torque converter employed. Thespeed ratio at which the converter is operating may be measured by anyform of differential mechanism either mechanically or electricallyresponsive to the difierence in speeds between the input and outputshafts of the converter. However, a novel form of indicating means whichis exceedingly simple in construction is illustrated in Figures 2, 7 and8. As best shown in Figure 7, the indicating device, indicated generallyat I41, is in the form of a magnetic eddy current coupling comprising adriving element I48 and a driven element I49, the driving element, beinglocated entirely within a cup-shaped depression in the driven elementbut being entirely disconnected therefrom. The driving and drivenelements are independently journaled in a suitable casing I50 by meansof antifriction bearings. Thus, the driving element is supported upon apair of ball bearings I5I and I52 and the driven elementis supportedupon a pair of ball bearings I53 and I54.

The driving element is preferably formed as a multiple permanent magnetand the driven element I49 is formed of an electrically conductivematerial, in accordance with the usual practice in constructingelectromagnetic couplings. The driving element I48 is rotated by anysuitable means at a speed in proportion to the difference in speedsbetween the input and output shafts of the converter. This is readilyeiiected in the apparatus of the present invention by connecting thedriving element I48 to the difierential mechanism in the cooling unit 42by means of a speedometer cable, indicated generally at I55. Thespeedometer cable is constructed in the usual manner with a stationarytubular flexible housing I56 having one end fixed to the casing I50 ofthe indicator I41 and the other end connected to a suitable boss I51formed on the housing for gears and of the fan drive, as best shown inFigure 2. The inner rotating element I58 of the speedometer cable hasone end connected to a projection I59 on the shaft 52 of the fan drive,as shown in Figure 2, while its other end is fixed to the shaft I58which carried the driving element I48 of the indicating device.

As a result of the mechanism so far described,

it will be apparent that rotation of the driving element I48 of theindicating device in either direction will tend to effect correspondingrotation of the driven element I48, and that the rotating forcetransmitted between the elements I48 and I49 will be generallyproportional to the difference between their speeds of rotation. Aspiral spring ISI is provided to resiliently hold the driven element I49in a neutral position and to resist rotational movement of the elementfrom the neutral position in either direction. .One end of the springIBI is fixed to the hub I52 of the driven element I48 and the other endis fixed to a mounting screw I63 carried by the casing I50. The shaftI54 which carries the driven element I49 projects from the casing andsupports an indicating pointer I55 which cooperates with any suitableform of eiliciency and/or speed ratio indicating dial.

The preferred form of dial, indicated at I66 in The strength of themagnetic coupler and the strength a of the spring I6I, are so selectedthat the pointer will remain in a vertical position so long as thedriving element I48 is stationary and will assome a position rotatedfrom the vertical in a counterclockwise direction, as viewed in Figure7, when the output shaft of the converter is stationary and the inputshaft is operating at the normal operating speed of the engine duringhoisting. As a result of this arrangement, the pointer assumes itsvertical position when the driving element I48 is stationary and thus,in that position, indicates that the torque converter is operating atmaximum efliciency. Accordingly, as the speed ratio of the converterincreases beyond that of maximum eillciency, the pointer will swin in aclockwise direction through an angle of 90 when the speed ratio of theconverter is approximately double that of maximum efficieney. Theparticular form of dial illustrated is adapted for use in connectionwith a torque converter which reaches maximum eiliciency at a speedratio of .4 and, consequently, the righthand extremity of the arcuateline represents a speed ratio of .8. From the known emciency curve ofthe converter employed, the actual efficiency of the convertercorresponding to a plurality of positions of the pointer along thearcuate line, may be determined and marked on the dial in the mannerindicated in Figure '7. Likewise the corresponding speed ratios may beindicated along the horizontal line below the arouate line, asindicated. In general, it is desirable to operate the converter withinan efllciency range of five percent of its peak efllciency and,consequently, the dial is suitably marked at I61 to indicate theso-called efiicient range of the converter. It will be noted that theeflicient range of the particular converter to which the dial applies,ranges from a speed ratio of .25 to a speed ratio of .5.

It will be understood that the particular form of indicating device,disclosed in Figure 8, which incorporates a double acting spring, isrequired when the differential drive mechanism is designed to have azero rotative speed when the torque ratio of the converter is at maximumefficiency. If an ordinary diii'erential drive is used,

I the provision ofa manually shiitable transmission which can be shiftedunder load during hoisting operations, the driller is ableto instantlyadjust the speed ratios in the transmission as required to obtain themost effective drive connection to the hoisting drum. In this connectionthe automatic two-speed transmission great- 15/ facilitates the,operation of the unit and relieves the driller of the necessity ofmaking frequent speed ratio changes. Thus, for example, if the properspeed ratio has been selected in the transmission 9 for hoisting anygiven stand of drill pipe, the pointer I65 of the emciency indicatorwill move from its extreme left-hand position, as viewed in Figure '7,at the beginning of thehoisting operation when the starting torque ishigh upwardly along the arcuate line in a clockwise direction. If thetorque load falls oif to such a point that the pointer reaches-the matictwo-speed transmission 61 will automatically shift into a direct drivethereby returning the pointer to the minimum efficient speed ratio of.25. -Thereafter-further reductions in torque load may occur withouttaking the converter out of its eflicient speed ratio range. If thedriller observes that after the shift of the automatic transmissionto'direct drive, the pointer is swinging clockwise beyond the efllcientrange oi the converter he may instantly shift the manually 1 controlledtransmission 9 to a lower torque multiplication. ratio, or if the entirestand pipe is hoisted without a movement of the pointer I65 clockwise asfar asthe eflicient speed ratio range, he may instantly shift themanually controlled transmission to a higher torque multiplcation ratio.These shifts can be made during the hoisting operation and,consequently, insure that the drill pipe will be hoisted at the maximumpossible speed and efliciency at all times.

It is also preferred, as indicated in Figure 7, to incorporate in thecontrol box I I4 all other necessary indicating devices commonlyemployed in drilling operations, such as meters for indicating oilpressure, engine speed, water temperature, air pressure etc. It isparticularly important in connection with apparatus of the presentinvention to employ individual engine speed indicating devices because,due to the fact that three engines will be driving the hoisting drumduring the hoisting operations through individual torque What is claimedis:

1. A power transmission system, comprising a hydro-kinetic torqueconverter and a manually controlled change-speed transmission connectedin series with the torque converter and an indicating device forcontinuously indicating to the operator the relationship between thespeed ratio of the converter and the converter speed ratio range ofmaximum efllciency as a guide to indicate whena need exists to changespeed ratios in the transmission in order to effect operation of theconverter at an eflicient speed ratio. 2. A cable winding drum mechanismincluding a drum, a hydro-kinetic torque converter, a

driving connection between the converter andv drum including achange-speed transmission, and an indicating device for continuouslyindicating to the operator the relationship between the speed ratio ofthe converter and the converter speed ratio range of maximumefliciencyas a guide to indicate when a need exists to change speedratios in the transmission in order to effect operation of the converterat an-efllcient speed ratio, the speed ratio changing mechanism of saidtransmission being shiftable under load without disconnecting the driveconnection through the transmission.

3. A power transmission system, comprising a hydro-kinetic torqueconverter and a manually controlled change-speed transmission connectedin series with thetorque converter, and an indicating device forcontinuously indicating to the operator the relationship between thespeed ratio of the converter and the converter speed ratio range ofmaximum efilciency as a guide to indicate when a need exists to changespeed ratios in the transmission in order to efiectopconverters, theoutput speed of the three torque converters will be the same and,consequently, the torque delivered by each engine will be exactly thesame at any given engine speed. Accordingly, so long as the threeengines are operating at the samespeed, the driller knows all three aretaking their share of the load.

While only one form of the invention is illustrated and described, andthat form embodied in oil well drilling mechanisms, it is appreciatedthat the apparatus of the present invention may be modified as todetails of construction and employed in other connections withoutdeparting from the spirit of the invention or the scope of the appendedclaims. Moreover,

the automatic two-speed transmission unit 61.

while desirable for some purposes, forms no part of the inventionclaimed in the present application and, hence, may be omitted, ifdesired.

eration of the converter at an eiiicient speed ratio, said deviceincluding an indicating member, an indicating scale member associatedwith said indicating member, one of said members being movable relativeto the other between predetermined limits, said scale bearing indiciarepresenting efiiciency values which are distributed over the length ofthe relative movement and progressively decrease in both directionsalong the length of the scale from an intermediate point thereon,resilient means biasing said memhers into a relative position in whichthe indicating member is opposite the point of maximum efliciency onsaid scale, and differentially driven eddy current clutch means adaptedto be driven from the input and output of the converter for exerting aforce proportional to the extent that the speed ratio of the converterdeparts from the speed ratio of maximum efliciency and tending to movesaid members relatively away from said relative position of maximumefliciency.

4. A power transmission system, comprising a hydro-kinetic torqueconverter and a manually controlled change-speed transmission connectedin series with the torque converter, and an indicating device forcontinuously indicating to the operator the relationship between thespeed ratio of the converter and the converter speed ratio range ofmaximum efliciency as a guide to indicate when a need exists to changespeed ratios in the transmission in order to effect operation of theconverter at an eflicient speed ratio, said device including anindicating mem-- ber, an indicating scale member associated with saidindicating member, one of said members being movable relative to theother between predetermined limits, said scale bearing indiciarepresenting efiiciency values which are distributed over the length ofthe relative movement and progressively decrease in both directionsalong the length of the scale from an interme diate point thereon,resilient means biasing said members into a relative position in whichthe indicating member is opposite the point of maximum efliciency onsaid scale, a rotatable element for moving one of said members relativeto the other, a rotatable driving element, means for transmitting fromsaid driving element to said first element a torque proportional to therelative speeds between said elements, and differential means fordriving said driving element from the input and output of the converterat a speed proportional to the extent that the speed ratio oi theconverter departs from the speed ratio of maximum efiiciency and inopposite directions dependent upon whether the speed ratio of theconverter exceeds or is less than the speed ratio of maximum efficiency.

dicating member, an indicating scale member associated with saidindicating member, one of said members being movable relative to theother between predetermined limits, said scale bearing indiciarepresenting efliciency values which are distributed over the length ofthe relative movement and progressively decrease in both directionsalong the length of the scale from an intermediate point thereon,resilient means biasing said members into a relative position in whichthe indicating member is opposite the point of maximum efficiency onsaid scale, and differentially driven eddy current clutch means adaptedto be driven from the input and output of the converter for exerting aforce proportional to the extent that the speed ratio of the converterdeparts from the speed ratio of maximum efficiency and tending to movesaid members relatively away from said relative posiindicia representingefllciency values which are Ill) distributed over the length or therelative movement and progressively decrease in both directions alongthe length or the scale Irom an intermediate point thereon, resilientmeans biasing said members into a relative position in which theindicating member is opposite the point of maximum efilciency on saidscale, a rotatable element for moving one of said members relative tothe other, a rotatable driving element, means for transmitting from saiddriving element to said first element a torque proportional to therelative speeds between said elements, and dlflerential means fordriving said driving element from the input and output of the converterat a speed proportional to the extent that the speed ratio of theconverter departs from the speed ratio of maximum efllciency and inopposite directions dependent upon whether the speed ratio of theconverter exceeds or is less than the speed ratio of maximum efliciency.CHARLES M. OLEARY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,962,538 Toney June 12, 19341,990,810 Young Feb. 12, 1935 2,022,689 Rainsford Dec. 3, 1935 2,085,805Jessen July 6, 1937 2,142,248 Le Feure Jan. 3, 1939 2,175,940 JessenOct. 10, 1939 2,180,724 Sheldon Nov. 21, 1939 2,186,999 Stone et al Jan.16, 1940 2,242,945 Edwards May 20, 1941 2,262,747 Banker Nov. 18, 19412,302,714 Pollard Nov. 24, 1942 2,338,413 DeFalco Jan. 4, 1944 2,373,453Brunken Apr. 10, 1945 2,387,901 Haverstick Oct. 30, 1945 2,405,546Archer Aug. 13, 1946 FOREIGN PATENTS Number Country Date Great BritainAug. 21, 1936

